package org.test.hadoop.mapreduce;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

public class SplitWordSort {
	public static class SortMapper extends Mapper<LongWritable, Text, SplitWordWritable, NullWritable>{

		@Override
		protected void map(
				LongWritable key,
				Text value,
				Mapper<LongWritable, Text, SplitWordWritable, NullWritable>.Context context)
				throws IOException, InterruptedException {
			String wv = value.toString();
			if(wv.split("	").length==2){
				SplitWordWritable w = new SplitWordWritable(value.toString());
				context.write(w, NullWritable.get());
			}
		}
		
	}
	
	
	public static class SortReducer extends Reducer<SplitWordWritable,NullWritable, SplitWordWritable, NullWritable>{

		
		protected void reduce(
				SplitWordWritable inkey,
				Iterable<IntWritable> value,
				Reducer<SplitWordWritable, NullWritable, SplitWordWritable, NullWritable>.Context context)
				throws IOException, InterruptedException {
			context.write(inkey,  NullWritable.get());
		}
		
	}
	
	public static void main(String[] args) throws IOException, InterruptedException, ClassNotFoundException {
		Configuration conf = new Configuration();
		String[] otherArgs = new GenericOptionsParser(conf, args)
				.getRemainingArgs();
		if (otherArgs.length < 2) {
			System.err.println("Usage: SplitSort <in> [<in>...] <out>");
			System.exit(2);
		}
		Job job = new Job(conf, "Split word Sort");
		job.setJarByClass(SplitWordSort.class);
		job.setMapperClass(SortMapper.class);
		job.setCombinerClass(SortReducer.class);
		job.setReducerClass(SortReducer.class);
		job.setOutputKeyClass(SplitWordWritable.class);
		job.setOutputValueClass(NullWritable.class);
		job.setNumReduceTasks(1);
		for (int i = 0; i < otherArgs.length - 1; ++i) {
			FileInputFormat.addInputPath(job, new Path(otherArgs[i]));
		}
		FileOutputFormat.setOutputPath(job, new Path(
				otherArgs[otherArgs.length - 1]));
		System.exit(job.waitForCompletion(true) ? 0 : 1);
	}
}
